RNA polymerase II (RNA Pol II) is generally paused at promoter-proximal regions in most metazoans, and based on in vitro studies, this function has been attributed to the negative elongation factor (NELF). Here, we show that upon rapid depletion of NELF, RNA Pol II fails to be released into gene bodies, stopping instead around the +1 nucleosomal dyad-associated region. The transition to the 2nd pause region is independent of positive transcription elongation factor P-TEFb. During the heat shock response, RNA Pol II is rapidly released from pausing at heat shock-induced genes, while most genes are paused and transcriptionally downregulated. Both of these aspects of the heat shock response remain intact upon NELF loss. We find that NELF depletion results in global loss of cap-binding complex from chromatin without global reduction of nascent transcript 5' cap stability. Thus, our studies implicate NELF functioning in early elongation complexes distinct from RNA Pol II pause-release.

中文翻译：

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NELF 调节启动子近端步骤，与 RNA Pol II 暂停释放不同。

在大多数后生动物中，RNA 聚合酶 II (RNA Pol II) 通常暂停在启动子近端区域，根据体外研究，该功能归因于负延伸因子 (NELF)。在这里，我们表明，当 NELF 快速耗尽时，RNA Pol II 无法释放到基因体中，而是停在 +1 核小体二联体相关区域周围。到第二个暂停区的转变独立于正转录延伸因子 P-TEFb。在热休克反应过程中，RNA Pol II 迅速从热休克诱导基因的暂停状态中释放出来，而大多数基因则暂停并转录下调。NELF 损失后，热激反应的这两个方面都保持完好。我们发现 NELF 耗尽会导致染色质帽结合复合物整体丢失，但新生转录物 5'帽稳定性并未整体降低。因此，我们的研究表明 NELF 在早期延伸复合物中的功能与 RNA Pol II 暂停释放不同。